Publications by authors named "Robert H Chen"

Article Synopsis
  • Boron neutron capture therapy (BNCT) shows promise for treating life-threatening, end-stage malignant brain tumors, but optimal treatment parameters are still unclear.
  • A study of 34 patients revealed a 50% response rate and an 85.3% disease control rate, with no severe adverse effects noted.
  • The analysis identified key factors for better survival outcomes, suggesting that patients with a specific tumor-to-normal tissue uptake ratio, smaller tumor volume, and certain other characteristics could benefit more from BNCT.
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Background: Craniopharyngiomas are frequent hypothalamo-pituitary tumors in children, presenting predominantly as cystic lesions. Morbidity from conventional treatment has focused attention on intracystic drug delivery, hypothesized to cause fewer clinical consequences. However, the efficacy of intracystic therapy remains unclear.

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Evidence that synaptic vesicles (SVs) can be gated by a single voltage sensitive calcium channel (CaV2.2) predict a molecular linking mechanism or "tether" (Stanley, 1993). Recent studies have proposed that the SV binds to the distal C-terminal on the CaV2.

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Neurons communicate with their target cells primarily by the release of chemical transmitters from presynaptic nerve terminals. The study of CNS presynaptic nerve terminals, isolated as synaptosomes (SSMs) has, however, been hampered by the typical small size of these structures that precludes the introduction of non-membrane permeable test substances such as peptides and drugs. We have developed a method to introduce large alien compounds of at least 150 kDa into functional synaptosomes.

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We have continued to explore spirobenzazepines as vasopressin receptor antagonists to follow up on RWJ-339489 (2), which had advanced into preclinical development. Further structural modifications were pursued to find a suitable backup compound for human clinical studies. Thus, we identified carboxylic acid derivative 3 (RWJ-676070; JNJ-17158063) as a potent, balanced vasopressin V(1a)/V(2) receptor antagonist with favorable properties for clinical development.

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A series of substituted spirobenzazepines was prepared and evaluated as V(1a) and V(2) dual vasopressin receptor antagonists. Compounds 7p and 7q have been shown to be not only potent inhibitors of vasopressin receptors, but also have exhibited an excellent overall pharmaceutical suitability profile.

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A novel series of spirobenzazepines was synthesized and evaluated for V1a and V2 receptor antagonist activity. Compounds 8b, 8i, and 8k have shown selective V1a receptor antagonist activity. Compounds 8p and 8q were shown to be dual V1a/V2 receptor antagonists.

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A number of 2,5-disubstituted benzothiazepines were synthesized and screened for their ability to inhibit arginine vasopressin binding to the human V(2) and V(1a) receptor subtypes. The more active compounds were subsequently analyzed for their antagonist activity in in vitro functional assays. The SAR showed a preference for an acidic unit appended from the benzothiazepine scaffold.

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Synopsis of recent research by authors named "Robert H Chen"

  • - Robert H Chen's recent research primarily focuses on advanced therapeutic approaches in neuro-oncology, particularly evaluating boron neutron capture therapy (BNCT) for malignant brain tumors and intracystic drug delivery for pediatric craniopharyngioma patients.
  • - His work highlights the relationship between treatment parameters and patient survival outcomes, as seen in the analysis of 34 BNCT cases, while also addressing the efficacy and safety of less invasive intracystic therapies compared to conventional treatments.
  • - Chen has also contributed to neuroscience research, investigating synaptic mechanisms and novel methods to introduce large molecules into synaptosomes, which may facilitate further understanding of presynaptic communication and drug delivery within the central nervous system.